Refrigerant evaporator



Feb. 7, 1950 Filed March 20, 1948 l.. A. PHlLlPP 2,496,558

REFRIGERANT EvAPoRAToR 2 Sheets-sheet 1 nues/v6.6 H- PML/PP H Troia/verFeb. 7, 1950 L. A. PHILIPP REFRIGERANT EvAPoRAToR Firlgd Maren 2Q, 19482 Sheets-Sheet 2 IN V EN TOR.

Lnh//EE/vcf /17- PH/L/PP Patented Feb. 7, 1950 2&93558 BEFRIGEBANTEVAPORATOR Lawrence A. Philipp, Detroit, Mich., asslgnor toNash-Kelvinator Corporation, Detroit, Mich., a corporation o! MarylandApplication March 2., 1948, Serial No. 16,092

Claims. (Cl. 62-126) This invention relates generally to refrigeratingapparatus and more particularly to refrigerant evaporators therefor.

One of the objects of the present invention is to provide a refrigerantevaporator of improved construction and arrangement to increaseefllciency of heat absorption.

Another object of the invention is to provide a refrigerant evaporatorhaving an improved arrangement of a refrigerant flow passage to the endof accomplishing improved distribution of refrigerant and absorption ofheat throughout the evaporator.

Another object of the invention is to provide a refrigerant evaporatorhaving an improved flow passage of a character which enables uniformtemperatures throughout the width thereof on relative wide evaporatorswhich extend substantially across the entire width of the refrigeratorcabinet.

Further objects and advantages of the present invention will be apparent'from the following description, reference being had to the accompanyingdrawings, wherein a preferred form of the present invention is clearlyshown.

In the drawings:

Fig. 1 is a front view partly broken away of a refrigerator including myimproved refrigerant evaporator;

Fig. 2 is a top plan view of the evaporator;

Fig. 3 is a rear view of the evaporator;

Fig. 4 is a bottom view of the evaporator;

Fig. 5 is a cross sectional view of the evaporator taken along the line5--5 of Fig. 3; and

Fig. 6 is a substantially diagrammatical view of the evaporator and ofother units of a refrigerating system.

Referring to the drawings by characters of reference, the numeraldesignates generally a refrigerator cabinet of the household type. Thecabinet 20 has a food storage compartment 21 which may be closed at thefront thereof by a hinged door 24. Immediately below the food storagecompartment 22, a. machinery, or condensing element compartment 26 ispreferably provided and may be closed at the front of the cabinet by ahinged door 28. My evaporator, designated generally by the numeral 30,may be located in the upper region of the food storage compartment 22and may be suspended from the cabinet top wall by suitable brackets 32.

In construction, the evaporator III is preferably of general L-shape incross section having a horlzontal leg or bottom wall and a vertical legor rear wall 88. Preferably, the evaporator Il extends substantiallyentirely across the width of the food storage compartment 22. A top wall40 having downturned,lopposite sides 42 may be provided to form,together with the L-shaped evaporator 30, a box-like container suitablefor the storage of ice trays (not shown), food stuffs, and other thingsto be frozen. Access to the freezing compartment of the container may behad at the front thereof which may be closed by an interior door 41. r

In accordance with my invention, I provide a refrigerant flow passage inthe bottom and rear walls of the evaporator comprising, an inlet anddirect expansion portion 44, a flooded portion 46, a manifold 48 and anaccumulator 50. The direct expansion portion 44 and the flooded portion4B of the refrigerant passage are relatively laterally positioned andextend substantially from the front edge of the evaporator bottom wall38 rearwardly and continue partway up the evaporator rear wall 36. Abovethe direct expansion and flooded portions of the refrigerant flowpassage in the evaporator rear wall 3B is the manifold 48, and abovethis is the accumulator 50. The manifold 48 and the accumulator 58extend substantially parallel and preferably substantially entirelyacross the width of the evaporator vertical wall 38, adjacent the topthereof. As shown, the manifold 48 and the accumulator 50 are connectedor are in communication at their opposite ends. Also, spaced passages 52may be provided, interconnecting the manifold and the accumulatorintermediate their ends to increase flow capacity for passage ofrefrigerant upwardly into the accumulator.

The evaporator 30 may be constructed of sheet material, such as a pairof thin steel sheets 54 and 56 which may be formed to provide the hereinmentioned refrigerant flow passage therebetween. The sheets 54, 56 aresuperimposed flat .against each other and may be secured and sealedaround their peripheral edges by welding or by any other suitable means.In Fig. 6, the numeral 58 designates the bend line along which thesheets 54, 5B are bent to form the L-shaped evaporator.

Further ln accordance with my invention, I arrange the direct expansionportion 44 of the refrigerant flow passage to extend in slnuous formacross the evaporator, and I provide for decreasing resistance torefrigerant flow through the passage by` alternately decreasing andincreasing ow capacity of adjacent runs of the slnuous passage. To thisend, I provide single passage runs manifold 48 to serve as a header.

l0, alternating with double or pairs of parallel Passage runs 62. Bythis arrangement, refrigerant entering the evaporator inlet, as at64,11ows through the first single run 60, then is divided to flowthrough the adjacent pair of parallel runs 62 and then through the nextsingle run and so on preferably across substantially two-thirds of theevaporator walls. Thus, at the parallel runs 82, resistance to flow isdecreased and at the single runs is increased to control evaporationthroughout the length of the passage. At the end of the last of the runs60, the refrigerant flows into the flooded portion 46 of the evaporator.This flooded portion of the evaporator 30 comprises a number of parallelpassages 66 connected adjacent the front edge of the evaporator by acommon connecting passage or manifold 68, and connected at their upperends to the underside of the manifold 48. During operation Qf the systemthe liquid level in the flooded section may be in the manifold 48 whichwould enable the If desired for certain operation the system may becharged with refrigerant to maintain this liquid level in theaccumulator 50 during operation of the system.

The top wall 40 of the container may be refrigerated by a refrigerantevaporator coil or conduit 10. This evaporator coil 'l0 may be arrangedto extend sinuously over the upper surface of the top wall 40 as shown,for example, in Fig. 2, Clamps 12 or other suitable means may beprovided to hold the evaporator coil down against, in good heatabsorbing relationship with, the container top wall 40. Liquidrefrigerant may be delivered from a suitable refrigerant condenser 14 tothe inlet of the evaporator 1li, through a small diameter or capillarytube 16. From the outlet of the evaporator 10, refrigerant flows intothe evaporator 30, at the inlet 64 of the direct expansion flow passageand passes through the passage portion 44 flowing first in a single run60 and then through a pair of parallel runs 62 and then through the nextsingle run 60 and so on, finally passing into the flooded portion 46 ofthe evaporator. These alternate, parallel runs 62 provide increased flowcapacity and thus decrease resistance to flow of refrigerant withaccompanying decrease in pressure between the high and low sides of thesystem. From the flooded portion of the evaporator 30 and from themanifold 48 gaseous refrigerant rises to the top of the accumulator 5Uwhere it is drawn ofi' by and returned to a motor-compressor unit 80.through a refrigerant return conduit 82.

From the foregoing description, it will be noted that I have provided arefrigerant evaporator having an improved arrangement of refrigerantflow passageways in which the refrigerant is allowed to expand directlyin passing through a portion of the passageway which is so constructedas to alternately effect restricting and expansion of the refrigerant.In addition. I have provided an improved refrigerant evaporator of theabove mentioned character in which the refrigerant passageway includesboth direct expansion and flooded type expansion along the bottom of anevaporator. In the arrangement disclosed herein, I have found that theevaporator operates at uniform temperature across its entire width.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings, wherein a preferred form of the present invention is clearlyshown.

4 I claim:

l. A refrigerant evaporator comprising, wall means, a refrigerantaccumulator formed in and by said wall means, a sinuous refrigerantpassage extending from an inlet partway along and in said wall means fordirect expansion of Arefrigerant passing therethrough, and a series ofconnected parallel passages extending along another portion of said wallmeans laterally of and parallel to said sinuous passage and connected tothe outlet of said sinuous passage and also connected to the inlet ofsaid accumulator.

2. A refrigerant evaporator comprising, a wall, a sinuous or seriescircuit portion of a refrigerant passageway extending along and in aportion of said wall, said series circuit portion of said passagewayhaving alternately large and small flow capacity portions along thelength thereof, a plurality of parallel passages in said wall positionedlaterally of and parallel to said sinuous portion of said refrigerantpassageway and communicating with a small flow capacity portion of therefrigerant passageway, and an accumulator connected adjacent one endthereof to said parallel passages and overlying ends of said sinuouscircuit portion.

3. A refrigerant evaporator comprising a wall section having a headerextending laterally thereacross, parallel passages having their outletends connected to one end section of said header and a serpentinepassage on said wall section positioned laterally of and extendingparallel to said parallel passages and below said header with saidserpentine passage being arranged with its outlet end connected to theinlet ends of' said parallel passages.

4. A refrigerant evaporator comprising, superimposed L shaped sheetsforming bottom and rear walls of a storage container, a sinuousrefrigerant passage formed between and by said L shaped sheets, saidpassage having alternate relatively large and relatively small flowcapacity portions in parallel relationship spaced widthwise of saidsheets and terminating intermediate the side edges thereof in one of therelatively small flow capacity portions, said passage also havingrelatively long run portions in said bottom wall and relatively shortrun portions in said rear wall, an elongated refrigerant accumulatorformed by and between said sheets in said rear wall, said accumulatorextending transversely of said runs along and above said short runportions and beyond said relatively small flow capacity terminalportion, and a series of parallel passages formed by and between saidsheets beneath an end portion of said accumulator, said series ofparallel passages being parallel to said runs and laterally positionedtherewith having an inlet connected to said relatively small flowcapacity portion and having individual outlets connected to saidaccumulator.

5. A refrigerant evaporator comprising, a pair of superimposed L shapedsheets forming a bottom wall having front and side edges and forming arear wall having side and top edges, a refrigerant passage formed by andbetween said sheets having an inlet in said rear wall adjacent one edgethereof, said passage extending from said inlet sinuously crosswise ofsaid walls over more than half of said walls with the runs of saidpassage extending from said front edge rearwardly and partway up saidrear wall, a refrigerant accumulator formed by and between said sheetshaving a pair of connected parallel passages extending aerosssubstantially the entire width of said rear wall above the turns of saidsinuous passage, and a series of individual refrigerant passages formedbetween and by said sheets parallel to each other and to the runs ofsaid sinuous passage, said series of passages being individuallyconnected to the outlet end of said sinuous passage and beingindividually connected t0 said accumulator.

LAWRENCE A. PHILIPP.

6 americas crrnn The following refeences are of record in the le of thispatent:

,5 UNITED STATES PATENTS Number Namo Date 2,109,986 Atchison Mar. 1,1938 2,110,002 Lichtenberg Mar. 1, .1938 2,117,861 Steenstrup May 17,1938 Newman Sept. 9, .1941

